Abstract: A portable, hand-held fluid tester for testing and analyzing process fluids is provided with a volume controlled fluid reservoir. The test fluid reservoir is connected by a spillway to an overflow reservoir to provide more consistent and accurate fluid volumes for measurement. Improved mounting of electrodes in the test reservoir and connection to a testing printed circuit substrate provides for ease of assembly. A special temperature probe arrangement is also provided in a preferred embodiment.

Abstract: A method and apparatus are set forth which enables a gas chromatographic column output to be connected with a pulse discharge chamber in which chemically bound chlorine in volatile organic or inorganic samples is measured. A spark discharge is formed in the chamber to ionize and excite helium molecules to a metastable state. In turn, that transfers excitation to a trace of krypton gas in the chamber which is ionized, and the ionized krypton then preferentially binds with chemically bound chlorine. The latter binding occurs with the liberation of a photon centered at about 222 nanometers thereby defining a spectral region of interest which is measured by a photomultiplier tube to quantify chemically bound chlorine.

Abstract: Accuracy of capacitance measurements taken with flying probes--probes that are movable relative to each other and surfaces of an object containing circuits being tested (e.g. a printed circuit board)--is improved by dynamically applying corrections for stray capacitance as individual probes are selected for measurements. Measuring circuitry to which the probes are linked includes multiplexor circuitry. The latter stray capacitance encompassing the stray capacitance between the one movable probe and the other movable probes as well as the cabling between the latter probes and the multiplexor circuitry. For these measurements, the reference point is contacted either by a fixed conductor or another one of the movable probes (other than the probe aligned with the test point) that is currently usable for that purpose.

Abstract: A resistive fault location method and apparatus are used on communication and power cables. Two instruments are connected to opposite ends of the faulted conductor. Each takes a series of voltage and current measurements that are then processed to determine the distance from each end of the conductor to the fault. To eliminate voltage and current transients, the data collected is statistically analyzed and data that is analyzed as being affected by transients is discarded. The remaining data is taken as being steady state data. This eliminates any requirement for simultaneous measurements at opposite ends of the conductor and accounts for any situation where local transients at the two ends of the conductor are different at any given instant.

Abstract: In a system for locating the position of a transmitter, a platform containing an antenna is moved through a measurement path. The frequency received by the antenna is measured at measurement points distributed along a measurement path. The frequency is measured by cross correlating coherent pulses of the received frequency signal. An inertial navigation system on the platform indicates the position of the measurement path. A computer determines estimated locations by non-linear least squares convergence starting from trial locations. The non-linear least squares convergence is based on the frequency equation for the received frequency ##EQU1## in which f.sub.0, is the transmitter frequency, V is the antenna velocity and r is the range of the transmitter. The computer evaluates a cost function derived from the frequency equation, for each location estimated by the non-linear least squares convergence and selects the estimated location with the lowest cost function as the best solution.

Abstract: A composite capacitive sensor device for use at least up to 1300.degree. C. and 40 bar, including a coaxial cable comprising a conductive sleeve (10) and an inner conductor (21), which are separated by a first insulator (19), and a probe (1) comprising elements which are all refractory and anticorrosive, which are respectively connected to the end portions of said cable and which comprise a metal housing (2) and an electrode (4) having a flat surface (4a) of larger area than the cross-sectional area of the inner conductor, which elements are separated by a second insulator (9) associated with locking means (3, 16) and are secured by means which are all refractory and anticorrosive (11a-11e).

Abstract: A capacitance gauge for measuring changes in the thickness of dielectric film, such as plastic film, is automatically temperature and humidity compensated by utilizing a primary measurement sensor and a reference sensor which monitors changes in perceived capacitance caused by ambient temperature and humidity changes or other environmentally induced interferences. The reference sensor counterbalances in an equal an opposite fashion, and thereby automatically cancels, any imbalance in the primary sensor caused by temperature, humidity, or other, fluctuations. An improved film transport assembly for serially examining plastic film material which eliminates errors in thickness measurement location and eliminates variation in distance between individual sensor readings, while at the same time allowing the user of the invention to select from a full variable range of distances between individual sensor readings and also allows accurate positioning of the film in the sensor.

Abstract: A method and apparatus for characterizing dimensions and parasitic capacitance between integrated-circuit interconnects are disclosed. The apparatus is a test structure including at least two substantially identical oscillators, at least two substantially identical counters, and a pulse generator. Each of the oscillators is connected to an integrated-circuit interconnect. Each of the counters is coupled to a respective oscillator. The pulse generator is utilized to inject a series of fixed-length clock pulses to each of the oscillators such that the parasitic capacitance of the integrated-circuit interconnects can be characterized by the ratio of oscillation periods of the oscillators to parasitic capacitances of the integrated-circuits.

Abstract: A power supply voltage (Vcc) is applied to a dummy capacitor having a capacitance identical to that of a bypass capacitor to generate an excessive current. The excessive current is subtracted from a current flowing through an IC and the bypass capacitor to obtain a power supply current (Icc) of the IC. The time required for measuring power supply current (Icc) of the IC is reduced since it is not necessary to wait for attenuation of the excessive current of the bypass capacitor.

Abstract: A microliter-sized metastable ionization device with a cavity, a sample gas inlet, a corona gas inlet and a gas outlet. A first electrode has a hollow and disposed in the cavity and is in fluid communication with the sample gas inlet. A second electrode is in fluid communication with the corona gas inlet and is disposed around the first electrode adjacent the hollow end thereof. A gap forming means forms a corona gap between the first and second electrodes. A first power supply is connected to the first electrode and the second power supply is connected to the second electrode for generating a corona discharge across the corona gap. A collector has a hollow end portion disposed in the cavity which is in fluid communications with the gas outlet for the outgassing and detection of ionized gases. The first electrode can be a tubular member aligned concentrically with a cylindrical second electrode. The gap forming means can be in annular disc projecting radially inwardly from the cylindrical second electrode.

Abstract: A wafer probe system includes a plurality of vertical-parallel probe pins having a spring formed in a center portion thereof to provide a contact force control area. The spring being formed according to a predetermined shape having a known stress-strain profile. In one embodiment, a first spring shape results in a probe tip contact force that is approximately constant after an initial vertical displacement of the probe tip. In an alternate embodiment, a second spring shape formed in the probe pin results in decreasing probe tip contact force with increasing vertical displacement of the probe tip. A canted probe tip end permits creation of an X-Y force component to facilitate penetration of the passivation layer. The canted tip portion also permits non-rotatable alignment of the probe pins in a probe card to thereby prevent contact of one probe pin with another.

Abstract: In a microwave resonator for continuous spectroscopic gas analysis with a microwave cavity having dimensions depending on the operating frequency and a setting for a low quality Q of its base mode and microwave reflectors disposed at its opposite ends and including a round hollow conductor part and a co-axial conductor part separated by a pressure-tight dielectric window, an internal conductor part is axially movably supported in the coaxial conductor part by the microwave reflector at one end of the co-axial conductor part, the other reflector being axially movable for tuning the resonator to a maximal absorption frequency and a by-pass line extends past the co-axial conductor part in the area of the dielectric window and has a short branch connected to the co-axial conductor part and including a restrictor for supplying only a relatively small flow of gas from the bypass line to the conductor part of the microwave resonator.

Abstract: Frequency domain reflectometer and method of determining severity of faults in a transmission line are disclosed. The reflectometer compensates for attenuation effects in the transmission line when determining severity of faults. In general, the reflectometer applies a sweep signal to the transmission line in order to obtain a reflected sweep response signal. Then, the reflectometer obtains a sweep response spectrum from the reflected sweep response signal. The reflected sweep response signal includes a plurality of spectral peaks which represent the frequency components of the reflected sweep response signal. Then, the reflectometer determines a first attenuation compensation factor for a first spectral peak of the reflected sweep response spectrum.

Abstract: A failure of a detecting circuit such as an ion current detecting circuit for detecting a combustion condition of an engine can be diagnosed at a stage for detecting a combustion condition by a combustion condition detecting apparatus equipped with a malfunction diagnosing apparatus. The engine combustion condition detecting apparatus equipped with the malfunction diagnosing apparatus is arranged by a sensing circuit for sensing an ion current flowing through a combustion chamber, a misfire judging means for judging misfire occurred in the engine in response to the detection signal derived from the sensing circuit, and a malfunction judging means for judging malfunction of the sensing circuit.

Abstract: A method of measuring electrical characteristics of a molecule including providing a first metal contact having a major surface, an insulating layer overlying the major surface of the first metal contact and a second metal contact overlying the insulating layer so as to have an edge spaced a molecular distance from the major surface of the first metal contact. A conductive organic molecule including a metal binding group is coupled between the metal contacts.

Abstract: A test fixture for testing the operation of a device having components installed at a first location. The components are connected to associated apparatus installed at a separate second location, and the components collectively have electrical inputs and outputs connected to a control at the second location. The test fixture has a housing and a plurality of output conductors at the first location. First ends of selected ones of the plurality of output conductors are connectable to selected ones of the inputs and outputs of the components. A power supply and a plurality of switches are mounted to the housing. Each of the plurality of switches has one contact connected to the power supply and another contact connected to a second end of respective one of the plurality of output conductors, whereby actuating one of the switches causes a respective one of the components to operate.

Abstract: A voltage measurement instrument such as a digital multimeter is provided with transient overvoltage input protection. Internal walls are integrally molded with the instrument case and disposed in close proximity to the input receptacles and terminals to separate conductive surfaces and provide transient overvoltage barriers. Top and bottom wall portions are fitted together in tongue-and-groove fashion to increase the creepage and clearance path without increasing the linear distance between conductive surfaces. This arrangement also allows the instrument to maintain a low profile.

Abstract: An apparatus for monitoring the current flow through a variable load such as various lengths of heater cables. The apparatus can detect a wide range of currents so that the size of the load can vary.

Abstract: An evaluation method for a test semiconductor device having at least two wiring patterns disposed in parallel, wherein: at least one wiring pattern is grounded; a pulse voltage is applied between the grounded wiring pattern and an adjacent wiring pattern; a time required for the pulse to reciprocate along the wiring patterns and a value of a voltage including a reflected voltage between the wiring patterns are measured to judge a presence/absence of a wiring breakage or a wiring short circuit and to locate a wiring breakage point or a wiring short circuit point.

Abstract: A testing device for qualitatively or quantitatively sensing an electrochemical or analogous reaction at the surface of a test strip (46), the current flowing or charge accumulated at the test strip being processed by electronics (50) to generate a current signal suitable for activating a display (52) typically in the form of a thermochromic layer.